Engine Mechanical - 6.5l v8 Diesel - VIN [y,s,f] GMC Savana I

MODEL IDENTIFICATION

MODEL IDENTIFICATION - TRUCKS

ENGINE IDENTIFICATION

Note. For repair procedures not covered in this article, see ENGINE OVERHAUL PROCEDURES article in GENERAL INFORMATION.

Engine can be identified by eighth character of Vehicle Identification Number (VIN). VIN is stamped on a metal plate, on the top left end of the instrument panel, near the windshield. See ENGINE IDENTIFICATION CODES table. Engine can also identified by engine identification (ID) number, stamped on cylinder block on engine-to-transmission mating flange, near left cylinder head.

ENGINE IDENTIFICATION CODES (6.5L DIESEL)

VALVE CLEARANCE ADJUSTMENT

Engine is equipped with nonadjustable hydraulic valve lifters.

FUEL INJECTION PUMP TIMING ADJUSTMENTS

Note. The scan tool procedures listed are referenced to the Tech 2 Diagnostic Scan Tool (7000081). If the engine or front cover has been removed, a Diagnostic Trouble Code (DTC) 1214 is set. If the PCM and fuel injection pump have been replaced, perform a TDC offset clear and relearn procedure before setting fuel injection pump timing.

TDC Offset Clear & Relearn (Turbo/EFI)

1. Install scan tool and start engine. Run vehicle until Engine Coolant Temperature (ETC) is greater than 170°F (77°C). Clear all DTCs. With key on and engine off, hold accelerator pedal in wide open throttle position for a minimum of 45 seconds. Turn ignition off for 30 seconds.
2. Start engine. Verify with scan tool that TDC offset has been cleared to 0. If not, repeat previous procedure. As soon as ECT is greater than 170°F (77°C) and engine speed is less than 1500 RPM, PCM will automatically learn new offset. New offset should be -0.25 - (-0.75). If not, see «TDC OFFSET ADJUSTMENT (TURBO/EFI)»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__tdc-offset-adjustment-turboefi) or «TDC OFFSET ADJUSTMENT (NON-TURBO/MECHANICAL FUEL INJ. MFI)»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__tdc-offset-adjustment-non-turbomechanical-fuel-inj) .

TDC Offset Adjustment (Turbo/EFI)

If TDC Offset is out of range, turn engine off, loosen fuel injection pump flange nuts. Turn fuel injection pump slightly (one mm = 2 degrees).

1. To advance timing, rotate pump toward driver's side.
2. To retard timing, rotate pump toward passenger's side.

Note. Repeat TDC offset relearn procedure. It may be necessary to adjust fuel injection pump several times until correct offset is achieved.

TDC Offset Adjustment (Non-Turbo/Mechanical Fuel Inj. MFI)

1. Set cylinder No. 1 to TDC. Remove fuel injection pump. See «FUEL INJECTION PUMP»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf). Install TDC scribe in injection pump mounting location (without gasket). Slot in fuel injection pump gear should be in vertical 6 o'clock position. If not, remove TDC scribe and rotate engine 360 degrees.
2. Install TDC scribe to pump gear. (Scheme 1) Install and finger tighten 10-mm nut to upper housing stud to hold tool flange. Tighten large bolt on left and 10-mm nut. Ensure crankshaft did not rotate and scribe did not bind. Strike scribe with a mallet to mark TDC on front housing. Remove scribe. Install fuel injection pump. Set fuel injection pump timing. See «FUEL INJECTION PUMP TIMING»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__fuel-injection-pump-timing-adjustment-procedure).

Scheme 1

Fuel Injection Pump Timing (Timing Marks)

Look for timing marks where fuel injection pump flange mates with engine front cover. At factory, a static timing mark (straight line) and a dynamic timing mark (oval) are scribed in this area. (Scheme 2) Replacement pumps do not have a dynamic timing mark on them. Some replacement pumps have a static timing mark. If replacement pump has a static timing mark on it, align static marks during installation. If replacement pump does not have a static timing mark on it, scribe one on it (needed for movement reference during adjustment procedure).

Scheme 2

Fuel Injection Pump Timing Adjustment Procedure (EFI/MFI)

1. Connect scan tool. Run vehicle until coolant temperature is greater than 170°F (77°C). Leave engine running. Using scan tool, activate TIME SET (if time set has been activated correctly, DES. INJ. TIME on scan tool will read 0.0 degrees).
2. If engine does not stall, go to next step. If engine stalls, loosen pump nuts. Slightly rotate pump toward driver's side of vehicle. Tighten nuts. Repeat step 1 .
3. Observe ACT. INJ. TIME value (this is the current timing). If timing is not 3.5 degrees BTDC, shut engine off. Loosen pump nuts. Rotate pump as necessary (one mm = 2 degrees). Tighten pump nuts. Start engine. Observe ACT. INJ. TIME value. If necessary, repeat adjustment procedure until average fluctuation of ACT. INJ. TIME is 3.5 degrees.

TROUBLE SHOOTING

Note. To trouble shoot engine mechanical components, see appropriate table in TROUBLE SHOOTING - BASIC PROCEDURES article in GENERAL INFORMATION.

REMOVAL & INSTALLATION

Note. For reassembly reference, label all electrical connectors, vacuum hoses and fuel lines before removal. Also place mating marks on engine hood and other major assemblies before removal.

Removal & Installation (Commercial Van/Motorhome, Sierra, Suburban, Tahoe, Yukon, & "C" & "K" Series Pickup)

1. Disconnect batteries. If equipped, remove engine cover or floor panel. Drain cooling system. Remove upper fan shroud and fan. Disconnect upper radiator hose. Discharge A/C system using approved refrigerant recovery/recycling equipment. Disconnect A/C condenser lines, and remove condenser and compressor (if equipped). Remove generator from mounting bracket. Remove power steering pump and reservoir, and lay aside.
2. Remove upper intake manifold cover. Disconnect fuel line from fuel filter and disconnect fuel return line. Disconnect electrical connector for engine wiring harness extension harness assembly for fuel injection pump at cowl (firewall). Remove ground straps from cylinder heads. Disconnect heater hoses from heater core. Install engine lift bracket to rear of right cylinder head.
3. Raise and support vehicle. Remove lower fan shroud and lower radiator hose. Remove starter and flywheel cover. Remove torque converter bolts (A/T). Disconnect exhaust pipe from turbocharger. Disconnect exhaust pipes from manifolds (non-turbocharged). Disconnect cylinder block heater wires (if equipped) and battery ground cable from front of engine block.
4. Disconnect oil cooler lines from quick disconnect connectors at engine block (anytime oil cooler lines are disconnected from quick disconnect connectors, retaining clip must be replaced). Remove automatic transmission cooler lines from retaining brackets. Remove oil filter adapter and front drive shaft (4WD models). Remove bellhousing bolts.
5. Lower vehicle. Remove radiator. Support transmission assembly. Attach suitable lifting device to lift bracket attached to rear of right head, and A/C mounting bracket. Lift engine slightly and remove engine mount through-bolts. Remove engine from vehicle. To install, reverse removal procedure. Tighten all retaining nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table.

Removal & Installation (Express, G-Van & Savana)

1. Disconnect and remove battery. Remove interior engine cover. Remove air intake duct from throttle body. Remove air cleaner assembly, and drain cooling system. Remove coolant recovery bottle, headlight bezels, grille, bumper and lower valance panel. Remove hood latch, upper fan shroud and radiator support.
2. Discharge A/C system using approved refrigerant recovery/recycling equipment. Disconnect A/C condenser lines, and remove condenser (if equipped). Remove radiator, radiator hoses, fan and lower shroud. Remove drive belt and cooling fan. Remove engine wiring harness, and disconnect block heater (if equipped). Remove engine oil fill tube and engine oil level indicator tube. Remove A/C compressor from mounting bracket. Remove P/S pump and A/C mounting bracket. Remove generator and mounting bracket.
3. Remove upper intake manifold and lower intake manifolds. See «INTAKE MANIFOLD»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Remove turbocharger. See «TURBOCHARGER»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Remove exhaust manifolds. Remove fuel injection pump. See «FUEL INJECTION PUMP»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Remove transmission oil level indicator tube and transmission shift cable connector. Raise and support vehicle. Remove starter. Remove flywheel cover and torque converter bolts (A/T). Remove engine oil cooler lines form engine and retaining brackets. Remove bellhousing bolts.
4. Lower vehicle. Install a length of chain using either engine lift brackets on rear of right cylinder head and front of left head or equivalent attaching bolt. Support transmission with a strap between frame rails. Lift engine slightly and remove engine mount through-bolts. Remove engine from vehicle. To install, reverse removal procedure. Tighten all nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table.

Upper Intake Manifold Removal (Commercial Van/Motorhome, Sierra, Suburban, Tahoe, Yukon, & "C" & "K" Series Pickup)

Note. DO NOT attempt to remove upper and lower intake manifold as an assembly. Damage to turbocharger could occur upon reinstallation.

Disconnect battery. Remove engine cover or floor panel (if equipped). Remove upper intake manifold cover. Remove clamp at turbocharger connection hose. Run a small flat-blade screwdriver between connection hose and upper intake manifold to loosen silicone sealer. Slide hose connecting upper intake manifold and turbocharger onto upper intake manifold. Remove EGR valve (L56 only). Remove brace from between turbocharger and upper intake manifold. Remove upper intake manifold bolts. Remove upper intake manifold.

Installation (Commercial Van/Motorhome, Sierra, Suburban, Tahoe, Yukon, & "C" & "K" Series Pickup)

To install, reverse removal procedure. Use NEW gaskets and "O" rings. Tighten bolts to specification. See TORQUE SPECIFICATIONS table.

Upper Intake Manifold Removal (Express, G-Van & Savana)

Disconnect negative battery cables. Remove interior engine cover. Remove air intake duct from upper intake manifold. Remove Crankcase Depression Regulator (CDR) valve from valve cover and air intake duct. Remove electrical harness, retaining brackets, transmission oil level indicator tube and rear A/C line from upper intake manifold. Remove upper intake manifold bolts. Remove upper intake manifold.

Installation (Express, G-Van & Savana)

Use NEW gaskets and "O" rings. Coat "O" ring between turbocharger and upper intake manifold with engine oil before installing on turbocharger. (Scheme 4) To install, reverse removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS table.

Lower Intake Manifold Removal (Commercial Van/Motorhome, Sierra, Suburban, Tahoe, Yukon, & "C" & "K" Series Pickup)

Disconnect negative battery cables. Remove upper intake manifold. See UPPER INTAKE MANIFOLD under INTAKE MANIFOLD. Remove fuel filter assembly from lower intake manifold. Remove EGR/Boost solenoids from intake manifold studs. Remove lower intake manifold bolts/studs and remove lower intake manifold.

Install NEW manifold gaskets and intake manifold. Using Teflon sealer, seal bolts No. 9, 11, 13 and 15. Apply threadlock sealer to bolts and studs No. 1-8, 10, 12, 14 and 16. Tighten intake manifold bolts in sequence to specification. (Scheme 3) See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure.

Lower Intake Manifold Removal (Express, G-Van & Savana)

Disconnect negative battery cables. Remove upper intake manifold. See UPPER INTAKE MANIFOLD under INTAKE MANIFOLD. Remove boost sensor relay and glow plug relay. Remove electrical harness retaining clips, ground straps and lower intake manifold studs. Remove lower intake manifolds.

To install, reverse removal procedure using NEW gaskets. Apply Teflon sealer to threads of studs No. 5 and 6. Apply threadlock sealer to remaining studs. (Scheme 4) Tighten intake manifold bolts in sequence to specification. See TORQUE SPECIFICATIONS table.

Scheme 3

Scheme 4

Scheme 5

Removal (Commercial Van/Motorhome Non-Turbocharged)

Disconnect negative battery cables. Raise and support vehicle. Using Glow Plug Connector Tool (J-39083) disconnect glow plug wires. Using Glow Plug Socket (J-41515-A), remove glow plugs. Disconnect exhaust pipes from exhaust manifolds. Lower vehicle. Remove exhaust manifold bolts. Remove exhaust manifolds.

Removal (Commercial Van/Motorhome, Sierra, Suburban, Tahoe, Yukon, & "C" & "K" Series Pickup - Turbocharged - Left Side)

Disconnect negative battery cables. Raise and support vehicle. Disconnect exhaust crossover pipe from manifolds. Using Glow Plug Connector Tool (J-39083), disconnect glow plug wires. Using Glow Plug Socket (J-41515-A) remove glow plugs. Remove exhaust manifold bolts. Remove left exhaust manifold from underneath vehicle.

Removal (Commercial Van/Motorhome, Sierra, Suburban, Tahoe, Yukon, & "C" & "K" Series Pickup - Turbocharged - Right Side)

Disconnect negative battery cables. Remove air cleaner box and intake duct. Remove turbocharger assembly from exhaust manifold. See TURBOCHARGER . Raise and support vehicle. Disconnect exhaust crossover pipe from manifold. Using Glow Plug Connector Tool (J-39083), disconnect glow plug wires. Using Glow Plug Socket (J-41515-A), remove glow plugs. Lower vehicle. Remove exhaust manifold bolts. Remove exhaust manifold.

Removal (Express, G-Van & Savana)

Disconnect negative battery cables. Remove interior engine cover from vehicle. Remove heat shield from turbocharger. Remove engine oil and also transmission oil level indicator tubes. Raise and support vehicle. Using Glow Plug Connector Tool (J-39083), disconnect glow plug wires. Using Glow Plug Socket (J-41515-A), remove glow plugs. Remove exhaust pipes from exhaust manifolds to turbocharger. Remove exhaust manifold bolts. Remove exhaust manifolds.

Installation

Install exhaust manifold. Tighten bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure.

Removal (Commercial Van/Motorhome, Sierra, Suburban, Tahoe, Yukon, & "C" & "K" Series Pickup)

1. Disconnect negative battery cables. Remove upper intake manifold cover. Remove CDR valve and tube from air cleaner. Loosen clamps on connector hose between upper intake manifold and turbocharger. Remove air cleaner extension and air cleaner assembly from turbocharger. Break seal between connector hose turbocharger compressor inlet and upper intake manifold by using a thin, flat screwdriver. Slide connector hose onto upper intake manifold.
2. Remove braces from turbocharger. Remove vacuum line from wastegate actuator. Remove oil feed line from turbocharger. Remove right wheel and inner splash shield. Remove oil drain tube and turbocharger attaching nuts. Remove exhaust pipe clamp and pipe from turbocharger outlet. Remove turbocharger. (Scheme 6)

Disconnect negative battery cables. Remove interior engine cover. Remove CDR valve and air cleaner intake duct from turbocharger. Remove upper intake manifold. See UPPER INTAKE MANIFOLD. Remove turbocharger heat shield and exhaust pipes connecting turbocharger to exhaust manifolds. Remove turbocharger mounting bolts. Remove turbocharger. (Scheme 7)

Inspection

1. Check intake and exhaust systems leading to and from turbocharger to ensure there is no foreign material that may cause damage to turbocharger during all levels of operation.
2. Check mating surfaces of exhaust manifold and turbocharger for cracks. Make sure turbocharger and exhaust manifold flanges are clean and free of foreign material. Use High Temperature Anti-Seize Compound (1052771) on all threaded fasteners that are connected to turbocharger.
3. Inspect oil feed and return passages in block, turbocharger and hoses. Ensure passages are clean and open.

Fill oil feed hole at top of turbocharger with clean oil while turning compressor wheel by hand. To install, reverse removal procedure. Apply small amount of silicone sealant (9985943) to turbocharger compressor inlet before installing connector hose. Tighten nuts and bolts to specification. See TORQUE SPECIFICATIONS table. (Scheme 5)

Fill oil feed hole at top of turbocharger with clean oil while turning compressor wheel by hand. To install, reverse removal procedure. Use NEW O ring between turbocharger and block and turbocharger and upper intake manifold. Tighten all retaining nuts and bolts to specification. See TORQUE SPECIFICATIONS table. (Scheme 6)

Scheme 6

Scheme 7

Removal

Disconnect negative battery cables. Remove interior engine cover (if equipped). Remove upper and lower intake manifolds. See INTAKE MANIFOLD. Disconnect injection lines, fuel inlet line and fuel return line from fuel injection pump. (Scheme 8) Disconnect all necessary wiring harness connectors and hoses from fuel injection pump. Remove oil fill tube. Rotate engine in order to gain access to bolts holding fuel injection pump driven gear to injection pump. Remove driven gear bolts. Remove fuel injection pump flange nuts. Remove fuel injection pump.

Install NEW flange gasket on fuel injection pump. Move locating stud on fuel injection pump hub to match elongated hole in driven gear. (Scheme 9) To finish installation, reverse removal procedure. Tighten all nuts and bolts to specification. See TORQUE SPECIFICATIONS table. Set fuel injection pump timing. See FUEL INJECTION PUMP TIMING ADJUSTMENT.

Scheme 8

Scheme 9

1. Disconnect negative battery cables. Remove upper and lower intake manifolds. See «INTAKE MANIFOLD»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Drain coolant. Remove upper and lower radiator hose. Remove by-pass hose from water pump and remove thermostat housing. Raise and support vehicle. Disconnect exhaust pipes from manifolds. Lower vehicle. Remove exhaust pipe from turbocharger and remove turbocharger (if equipped). See «TURBOCHARGER»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) .
2. Using Glow Plug Connector Tool (J-39083), disconnect glow plug wires. Using Glow Plug Socket (J-41515-A), remove glow plugs. Remove left and right exhaust manifolds. See «EXHAUST MANIFOLD»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Discharge A/C system using approved refrigerant recovery/recycling equipment. Remove A/C compressor and mounting bracket. Remove generator and mounting bracket. Remove vacuum pump and ground strap from rear of cylinder head.
3. Remove injection lines from injection pump and injector nozzles. Remove injection lines. See «FUEL INJECTION PUMP»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Remove oil level indicator tube. Remove heater hoses from heater core. Disconnect remaining wiring harness. Remove valve covers. Mark component location for reassembly reference. Remove rocker arm bolts and rocker arm shafts. See «ROCKER ARM ASSEMBLY»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__rocker-arm-assembly) . Note hardened upper end of push rod, indicated by paint stripe. Mark push rods if no paint stripe is visible. Remove push rods. Remove cylinder head bolts. Remove cylinder heads.

1. Disconnect negative battery cables. Remove interior engine cover. Remove upper and lower intake manifolds. See «INTAKE MANIFOLD»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Remove turbocharger. See «TURBOCHARGER»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Disconnect injection lines from fuel injection pump and injector nozzles. Remove injection lines. Remove valve covers. Drain coolant, and remove upper radiator hose. Remove thermostat housing, rear water jacket cover and gasket from cylinder heads.
2. Remove exhaust manifolds. See «EXHAUST MANIFOLD»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Remove power steering pump from mounting bracket. Discharge A/C system using approved refrigerant recovery/recycling equipment, and remove A/C compressor and mounting bracket. Remove oil level indicator tube. Remove generator and mounting bracket. Disconnect remaining wiring harness from heads, and set aside.
3. Using Glow Plug Connector Tool (J-39083), disconnect glow plug wires. Using Glow Plug Socket (J-41515-A), remove glow plugs. Mark component location for reassembly reference, and remove rocker arm bolts and rocker arm shafts. See «ROCKER ARM ASSEMBLY»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__rocker-arm-assembly) . Note hardened upper end of push rod, indicated by paint stripe. Mark push rods if no paint stripe is visible. Remove push rods. Remove cylinder head bolts, cylinder head and gasket.

1. Clean cylinder head and cylinder block gasket surfaces. Clean cylinder head bolt thread and bolt holes. DO NOT apply sealant to head gasket surface. Install cylinder head. Install head bolts and tighten in sequence to specification. (Scheme 10) Also, see «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table. Install push rods in original location with hardened end upward.
2. Rotate crankshaft until timing mark on crankshaft damper aligns with "0" mark on timing tab, then rotate crankshaft counterclockwise 3 1/2" (estimate this distance by aligning crankshaft damper mark with first lower water pump bolt). (Scheme 11)
3. Install rocker arm shafts, ensuring push rods are seated in rocker arms. Alternately tighten shaft bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table. To complete installation, reverse removal procedure.

Scheme 10

Scheme 11

Disconnect negative battery cables. Remove drive belts. Remove upper fan shroud from radiator. Raise and support vehicle. Remove lower fan shroud from radiator. Remove crankshaft pulley bolts and pulley. Remove crankshaft damper bolt and washer. Using Damper Puller (J-23523-F), remove crankshaft damper. Pry seal from cover.

Ensure seal area is free of burrs. Coat seal lip and crankshaft damper sealing surface with engine oil. Install new seal using Seal Installer (J-22101). Install crankshaft damper, washer and bolt. Tighten bolt to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure.

FRONT COVER

Note. Check and adjust fuel injection pump TDC and timing if front cover, timing chain, sprockets, fuel injection pump, or fuel injection pump gears are removed. See FUEL INJECTION PUMP TIMING ADJUSTMENT under ADJUSTMENTS.

Disconnect negative battery cables. Drain cooling system. Remove upper fan shroud from radiator, and remove serpentine belt. Raise and support vehicle. Remove lower fan shroud from radiator. Using Damper Puller (J-23523-F), remove crankshaft damper. Remove crankshaft position sensor from engine front cover. Remove bolts from engine front cover to oil pan. Lower vehicle. Remove water pump. Remove fuel injection pump drive gear from fuel injection pump. Remove front cover bolts and front cover. (Scheme 12)

Apply a 3/32 (2 mm) bead of silicone (GM/1052357) on front cover. Apply 3/16 (5 mm) bead of silicone sealer to front cover where cover meets oil pan. Install front cover and bolts. To finish installation, reverse removal procedure. Tighten all nuts and bolts to specification. See TORQUE SPECIFICATIONS table.

Scheme 12

TIMING CHAIN & SPROCKETS

Note. Check and adjust fuel injection pump TDC and timing if timing chain, sprockets or fuel injection pump gears are removed. See FUEL INJECTION PUMP TIMING ADJUSTMENT under ADJUSTMENTS.

Remove front cover. See FRONT COVER. Measure timing chain free play. See TIMING CHAIN FREE PLAY. Remove camshaft gear from camshaft sprocket. (Scheme 13) Note alignment of timing marks on crankshaft and camshaft sprockets. Remove camshaft sprocket and timing chain. Remove crankshaft sprocket (if necessary).

Timing Chain Free Play

1. Position dial indicator on front of cylinder block with dial indicator tip in contact with center of timing chain between sprockets. Pull chain away from crankshaft and adjust dial indicator to zero.
2. Push chain toward crankshaft, and note indicator reading. If chain deflection exceeds .80" (20.3 mm) on used parts or .50" (12.7 mm) on new parts, replace chain. Replace sprockets if worn.

Install crankshaft sprocket (if removed). Install camshaft sprocket and timing chain as an assembly, ensuring timing marks are aligned. (Scheme 13) Install camshaft gear, washer and bolt. Tighten camshaft gear bolt. Install front cover. See FRONT COVER. To complete installation, reverse removal procedure. Tighten all nuts and bolts and specification. See TORQUE SPECIFICATIONS table. Adjust fuel injection pump TDC and timing.

Scheme 13

1. Rotate engine until mark on crankshaft balancer is at 2 o'clock position, or until timing mark on crankshaft damper aligns with "0" mark on timing tab. Rotate crankshaft counterclockwise 3 1/2" (88 mm). Estimate this distance by aligning crankshaft damper mark with first lower water pump bolt, about 12:30 position. (Scheme 11) Remove intake manifold. See «INTAKE MANIFOLD»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf). Remove fuel injection lines and valve covers.
2. Remove rocker arm shaft bolts and rocker arm shaft. Mark component location for reassembly reference. To disassemble rocker arm shaft, insert a screwdriver into valve rocker arm shaft bore and break off end of nylon valve rocker arm retainers. Remove valve rocker arm retainers with a pair of pliers. Slide valve rocker arms from shaft.
3. If removing push rods, note paint stripe on hardened end of push rod (end closest to rocker arm). If no paint stripe is present, mark hardened end of push rod for reassembly reference.

Check rocker arms and shafts for scoring or other damage. Check push rods for bending, scoring or roughness. Check valve lifter guides and retainers for damage. Check oil passages in push rods for obstructions.

Reassemble rocker arm shafts using NEW nylon valve rocker arm retainers. Install push rods with hardened end upward in original location (if removed). Install rocker arm assembly in original location, ensuring push rods are seated in rocker arms. Install rocker arm shaft bolts. Alternately tighten shaft bolts to specification. See TORQUE SPECIFICATIONS table. Rotate engine by hand to ensure valves clear pistons. To complete installation, reverse removal procedure.

Remove intake manifold. See INTAKE MANIFOLD . Remove cylinder heads. See CYLINDER HEAD . Remove guide plate clamps, guide plates and lifters.

Note. Some engines are equipped with standard size and .010" (.25 mm) oversize diameter lifters. Bores fitted with oversize lifters are identified by a number 10 stamped on cylinder block pad, adjacent to lifter bore, and on top rail of cylinder case, above lifter bore. Oversize lifters are identified by a number 10 stamped on side of lifter.

1. Check for nicks, burrs or scoring on parts. Ensure lifter roller operates smoothly without excessive play and contains no flat spots.
2. Measure lifter oil clearance. If necessary, replace lifter with .010" (.25 mm) oversize lifter if resulting oil clearance allows.

1. Submerge NEW lifters in clean kerosene or diesel fuel and operate plunger several times. Coat lifter roller and bearings with Assembly Lubricant (1052365). Install lifter into original bore. Install guide plate and guide plate clamp. Tighten clamp bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table.
2. After all clamps are installed, rotate crankshaft by hand 2 complete turns to ensure free movement of lifters in guide plates. If crankshaft will not rotate, lifter(s) may be binding in guide plate.
3. To complete installation, reverse removal procedure. Tighten all retaining nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table.

1. Disconnect negative battery cables. Remove interior engine cover (if equipped). Drain cooling system. Discharge A/C system using approved refrigerant recovery/recycling equipment. Remove coolant surge tank, air cleaner assembly and air intake duct from turbocharger. Remove parking lamp assembly, grille, radiator support, auxiliary engine oil cooler (if equipped), A/C condenser and radiator.
2. Remove turbocharger (if equipped). See «TURBOCHARGER»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) . Remove cylinder heads. See «CYLINDER HEAD»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__cylinder-head) . Remove front cover. See «FRONT COVER»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__front-cover) . Remove oil pump drive gear. Remove hydraulic valve lifters. See «HYDRAULIC VALVE LIFTERS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__hydraulic-valve-lifters) . Remove timing chain and sprockets. See «TIMING CHAIN & SPROCKETS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__timing-chain-sprockets) . Remove camshaft thrust plate and spacer. Remove camshaft.

Inspect camshaft lobes for signs of flaking or flat spots. Measure camshaft journal diameter. Determine oil clearance. Replace camshaft and/or bearings as necessary if not within specification. See CAMSHAFT table under ENGINE SPECIFICATIONS.

Note. Replace all hydraulic lifters if installing new camshaft.

1. Coat camshaft journals with engine oil, and lobes with High Viscosity Oil with Zinc (12345501). Install camshaft. Install thrust spacer with inside chamfer toward camshaft. Install thrust plate.
2. Ensure camshaft end play is within specification. See «CAMSHAFT»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table under ENGINE SPECIFICATIONS. Install camshaft sprocket and timing chain, ensuring timing marks are aligned. (Scheme 13) To complete installation, reverse removal procedure. Tighten all nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table.

REAR CRANKSHAFT OIL SEAL

Note. Before new crankshaft rear oil seal is installed, CDR and crankcase ventilation system should be thoroughly inspected, and crankcase pressure should also be checked.

Disconnect negative battery cables. Remove interior engine cover (if equipped). Remove transfer case (if equipped). Remove transmission, clutch (M/T) and flywheel. For M/T, see appropriate article in CLUTCHES. Remove flexplate (A/T). For A/T, see appropriate TRANSMISSION REMOVAL & INSTALLATION article in TRANSMISSION SERVICING. Pry seal from housing.

1. Lubricate inner and outer diameter of seal with engine oil. Place seal on Seal Installer (J-39084). Position seal installer against crankshaft.
2. Mount seal installer on crankshaft flange. Rotate seal installer handle until installer bottoms on flange. Remove seal installer. Install flywheel, clutch (M/T) and transmission. To complete installation, reverse removal procedure. Tighten all nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table.

Note. Thermostat is located in coolant crossover, on top of engine. Engine is equipped with 2 thermostats.

Remove nut holding fuel bleeder Shraeder valve. Remove bolts from thermostat housing. Remove thermostats and seals. To install, reverse removal procedure.

1. Disconnect negative battery cables. Drain cooling system. Remove accessory drive belt, fan, pulley and upper and lower fan shrouds. Remove generator and bracket. Remove vacuum pump.
2. Disconnect coolant by-pass hose and lower radiator hose from water pump. Remove water pump bolts. Remove water pump and water pump plate as an assembly. Remove water pump plate-to-water pump bolt. Separate water pump from plate. (Scheme 14)

1. Apply Anaerobic Sealant (1052357) to sealing surface of plate and front cover. Install plate to pump with NEW gasket. Coat water pump bolt threads with Sealant (1052080).
2. Install pump and plate assembly to front cover with NEW gasket. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table. To complete installation, reverse removal procedure.

Scheme 14

Removal (Sierra, Suburban, Tahoe, Yukon, Commercial Van/Motorhome, & "C" & "K" Series Pickup)

1. Disconnect negative battery cables. Raise and support vehicle. Drain crankcase. Remove flywheel cover. On Commercial Van/Motorhome with coil spring suspension only, remove flexplate and transmission. See appropriate TRANSMISSION REMOVAL & INSTALLATION under TRANSMISSION SERVICING.
2. On all others, remove transmission, clutch (M/T) and flywheel. Remove flexplate (A/T). See appropriate TRANSMISSION REMOVAL & INSTALLATION under TRANSMISSION SERVICING. Disconnect exhaust pipes from manifolds. Remove long bolts from engine mounts. Raise and support engine. Remove oil pan bolts, oil pan and oil pan rear seal.

Disconnect negative battery cables. Remove engine oil indicator tube. Raise and support vehicle. Drain crankcase. Remove flywheel cover. Remove oil cooler lines at bracket and remove bracket. Remove oil pan bolts. Remove oil pan from engine.

Apply 3/16" (5 mm) bead of RTV sealant (GM/1052915) to oil pan sealing surface, inboard of bolt holes. Install oil pan rear seal. Install oil pan. Tighten oil pan bolts. To complete installation, reverse removal procedure. Tighten all nuts and bolts to specification. See TORQUE SPECIFICATIONS table.

OVERHAUL

Cylinder Head

Note. Resurfacing cylinder head is not recommended due to extremely close valve-to-piston clearances.

If surface warpage exceeds specification, replace cylinder head. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. DO NOT machine cylinder head surface. Measure cylinder head thickness (distance between valve cover gasket surface and cylinder head gasket surface). If thickness is less than specified, replace cylinder head.

Pre-Chamber

1. Inspect pre-chamber for surface cracks. Replace pre-chamber if surface crack length exceeds 3/16" or if crack reaches combustion chamber sealing mark. To remove pre-chamber, insert small nylon punch through injector hole. Drive pre-chamber from cylinder head.
2. To install pre-chamber, align pre-chamber with alignment notch in cylinder head. Using 1 1/4" (32 mm) socket and hammer, tap pre-chamber into bore.
3. Measure pre-chamber installed height in 2 or more locations where pre-chamber seats against head gasket shield and sealing ring. Ensure pre-chamber is even with cylinder head or does not protrude from cylinder head more than .002" (.05 mm). Pre-chamber must not be recessed in cylinder head.

Valve Springs

Measure valve spring pressure. Measure valve spring installed height between spring seat (or top of shim, if shimmed) and top of spring shield. Replace valve spring if pressure or installed height is not within specification. See VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS.

Valve Stem Oil Seals

Intake valve uses upper "O" ring seal. Exhaust valve uses upper "O" ring seal and lower umbrella seal, seated against cylinder head.

Valve Guides

Valve guides are part of cylinder head (not replaceable). If valve stem-to-guide oil clearance is not within specification, ream valve guides using Reamer Set (J-7049) and install oversize valves. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. Oversize valves are available in .003" (.08 mm) and .015" (.38 mm) oversize.

Valve Seat

No replacement procedure is available from manufacturer. Valve seats are induction hardened. Excessive removal of material may damage valve seat. Measure seat width and runout. See CYLINDER HEAD table under ENGINE SPECIFICATIONS.

Valves

Valves with .003" (.08 mm) and .015" (.38 mm) oversize stems are available for worn valve guides.

VALVE TRAIN

Note. Note paint stripe on hardened end of push rod (end closest to rocker arm). If no paint stripe is present, mark hardened end of push rod for reassembly reference.

Rocker Arm Assembly

1. To disassemble rocker arm assembly, insert screwdriver into rocker arm shaft bore. Break off end of retainer. Pull out retainer with pliers. Mark rocker arms for reassembly to original location on shaft. Remove rocker arms from shaft.
2. Inspect rocker arms and rocker arm shaft at mating surface for damage. Inspect push rods for bend and wear. Ensure oil passages are clear.
3. To assemble rocker arm assembly, coat rocker arms with engine oil and install on shaft in original locations. Center rocker arms with their corresponding holes on shaft. Install NEW nylon retainers with a 1/2" minimum diameter drift punch.

Hydraulic Valve Lifters

Engine is equipped with roller type hydraulic valve lifters. Lifters are serviced as complete assemblies only. Parts are not interchangeable between lifters.

CYLINDER BLOCK ASSEMBLY

Piston & Rod Assembly

1. Mark piston and rod assembly for installation to original bore. Mark rod and cap in relation to piston. Assemble rod to piston with rod bearing tang on same side of piston as piston crown indent.
2. Properly position ring end gaps around circumference of piston. (Scheme 15) Install piston and rod assembly in bore with piston crown indent toward outside of engine.

Fitting Pistons

1. Measure cylinder bore diameter .79" (20 mm), 3.8" (96 mm) and 6.1" (155 mm) below cylinder block deck surface. Measure piston diameter at 90-degree angle to piston pin and on pin center line. Determine piston clearance.
2. If clearance is not within specification, replace piston and/or machine cylinder bore. See «CYLINDER BLOCK»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) and «PISTONS, PINS & RINGS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) tables under ENGINE SPECIFICATIONS.

Piston Pins

Using a small screwdriver and Piston Pin Retaining Ring Installer (J39507), install retaining rings. Opening in an installed retaining ring should face downward (toward crankshaft).

Piston Rings

Note. Top compression ring uses a Keystone type (ring land is tapered). Piston ring side clearance cannot be measured.

Measure piston ring end gap and side clearance. If not within specification, replace piston and/or rings as necessary. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS. Install rings with mark on ring facing upward. Position ring end gaps on piston. (Scheme 15)

Scheme 15

Rod Bearings

Note. Some engines may contain both standard and .003" (.08 mm) oversize connecting rod bearings, identified by O.S. stamped on bearing cap lower end.

1. Mark rod caps in relation to rod for reassembly reference. Measure rod bearing journal out-of-round, taper and oil clearance. If measurement is not within specification, install NEW rod bearings. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table under ENGINE SPECIFICATIONS.
2. Undersize bearings may be used in combination with standard bearings to produce correct clearance. If clearance is not within specification after installing new bearings, replace crankshaft. DO NOT machine crankshaft. Ensure rod side play is within specification.

Crankshaft & Main Bearings

1. Mark main bearing caps in relation to cylinder block. Measure main bearing journal diameter, out-of-round and taper. Determine main bearing oil clearance.
2. If measurement is not within specification, replace main bearings. DO NOT machine crankshaft. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table under ENGINE SPECIFICATIONS.
3. Apply a thin film of RTV to crankshaft seal area of rear main bearing cap. Lightly oil cap bolt threads. Tap rear main bearing cap into place with brass or leather mallet. Install cap bolts, and tighten slightly. Align thrust bearing surfaces and measure crankshaft end play. See «THRUST BEARING»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf__thrust-bearing) .

Thrust Bearing

1. Main bearing No. 3 is thrust bearing. Tighten all other main bearing caps to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table. Tighten thrust bearing to 10 ft. lbs. (14 N.m). Tap crankshaft rearward then forward.
2. Tighten thrust bearing cap to specification. Measure crankshaft end play at front face of thrust bearing. If crankshaft end play is not within specification, replace thrust bearing or crankshaft. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table under ENGINE SPECIFICATIONS.

Cylinder Block

Measure warpage of cylinder block deck surface. If warpage exceeds specification, replace cylinder block. DO NOT machine cylinder block deck surface. See CYLINDER BLOCK table under ENGINE SPECIFICATIONS. If cylinder bore taper and out-of-round are not with specification, machine cylinder bore and/or replace piston.

ENGINE LUBRICATION SYSTEM

Pressurized lubrication is provided by gear-type oil pump. (Scheme 16) Camshaft drives oil pump through shaft of a gear-driven engine speed sensor. Lubrication flows through external oil cooler then into full-flow oil filter. Nonadjustable oil pressure regulator valve is located in oil pump body. Main oil gallery supplies oil through drilled passages to camshaft and crankshaft bearings. Oil flows through galleries to valve lifters then through hollow push rods to rocker arms.

Scheme 16

Note. Manufacturer recommends changing oil filter at every oil change.

Crankcase Capacity

Crankcase capacity is 7 quarts (6.6L) including oil filter change.

Oil Pressure

Normal oil pressure is 6 psi (41 kPa) at idle and 30-43 psi (207-296 kPa) at 2000 RPM.

Removal & Disassembly

1. Remove oil pan, oil pump and extension shaft. See «OIL PAN»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) under REMOVAL & INSTALLATION. Remove pump cover screws and pump cover. Mark gears so they may be reassembled with same tooth indexed. Remove idler gear, drive gear and shaft from pump housing.
2. Remove pressure regulator valve retaining pin from pump cover. Remove regulator valve components from pump cover. Note order of removal. DO NOT disassemble pick-up screen and pipe. Screen and pipe are serviced only as an assembly with pump.

1. Inspect pump body and cover for cracks or excessive wear. Inspect pump gears for damage or wear. Check drive gear shaft for looseness in pump body.
2. Check pressure regulator valve for fit in bore. Inspect inlet tube and screen assembly for damage. Replace entire pump assembly if damaged.

Reassembly & Installation

1. Install pump gears into pump body with marked gear teeth indexed. Reassemble remaining components in reverse order of disassembly. On Express, G-Van and Savana, place pump and extension shaft inside oil pan. Position oil pan in place.
2. On all models, install pump and extension shaft on engine, ensuring slot on top of extension shaft engages with drive tang on end of pump drive or vacuum pump. Tighten mounting bolt to specification. See «TORQUE SPECIFICATIONS»(/gmc/savana/i-1996-2002/remont/mechanical/#engine-mechanical-65l-v8-diesel-vin-ysf) table. Install oil pan.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL SPECIFICATIONS

GENERAL SPECIFICATIONS

CRANKSHAFT, MAIN BEARINGS & CONNECTING ROD BEARINGS SPECIFICATIONS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

CONNECTING RODS SPECIFICATIONS

CONNECTING RODS

PISTONS, PISTON PINS & PISTON RINGS SPECIFICATIONS

PISTONS, PINS & RINGS

CYLINDER BLOCK SPECIFICATIONS

CYLINDER BLOCK

ENGINE VALVES & VALVE SPRINGS SPECIFICATIONS

VALVES & VALVE SPRINGS

CYLINDER HEAD SPECIFICATIONS

CYLINDER HEAD

CAMSHAFT SPECIFICATIONS

CAMSHAFT

See also:
• ENGINE OVERHAUL PROCEDURES
• TROUBLE SHOOTING - BASIC PROCEDURES
• COMPUTER RELEARN PROCEDURES - GENERAL MOTORS
• ENGINE IDENTIFICATION CODES
• TDC OFFSET ADJUSTMENT (TURBO/EFI)
• TDC OFFSET ADJUSTMENT (NON-TURBO/MECHANICAL FUEL INJ. MFI)
• FUEL INJECTION PUMP TIMING
• UPPER INTAKE MANIFOLD
• UPPER INTAKE MANIFOLD
• ROCKER ARM ASSEMBLY
• FRONT COVER
• TIMING CHAIN FREE PLAY
• CYLINDER HEAD
• HYDRAULIC VALVE LIFTERS
• TIMING CHAIN & SPROCKETS
• THRUST BEARING